The Carbon Footprint of US Diets: New Research Linking Environmental Impacts to Food Choices and Diet Quality

Webinar
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Date:

May 16 2018, 1:00 PM - 2:30 PM EST

Description

Join the Tulane Center of Excellence in Maternal and Child Health, Tulane Prevention Research Center, and the American Public Health Association for a webinar discussion.

This webinar will:

Explain what is meant by a carbon footprint and how to calculate it for specific foods.

Describe the relationship between individual dietary choices and greenhouse gas emissions from food in the US context.

Explain the link between the greenhouse gas emissions of a diet and its overall nutritional quality.

Agriculture is a major contributor to climate change, representing 30-40 percent of greenhouse gas emissions globally, and about 10 percent in the US. Individual dietary choices contribute to this problem by influencing what gets produced. Our research addresses the environmental impacts of individual food choices in the US and their implications for diet quality.

We developed an approach to link environmental impacts of foods to data on adult diets reported in the 2005-2010 National Health and Nutrition Examination Survey. We constructed a distribution of the carbon footprint of one-day diets by ranking diets from low to high impact. Those in the top quintile (i.e. high-impact diets) had a carbon footprint close to eight times that of the bottom quintile. Shifting the top quintile diets to the mean resulted in a significant overall reduction in national greenhouse gas emissions. After scaling for energy intake, we examined the differences in food and nutrient content, and overall diet quality of these high and low-impact diets. The bottom quintile (i.e. low-impact) diets scored better on vitamin E, fiber and saturated fat, but not on calcium, vitamin D, and potassium. Overall diet quality as measured by the Healthy Eating Index was better in the low-impact group. These results suggest that food patterns with lower carbon footprints have a better overall diet quality and are more nutritious on several key dimensions.

Our analyses highlight the importance of utilizing individual dietary behaviors rather than just population means when considering diet shift scenarios and set the stage for further policy and scenario simulations aimed at aligning environmental and nutritional outcomes.

Watch the recorded webinar.(Note that Dr. Heller's recorded presentation contained a slight error. In discussing the emission reduction possible if the highest emitting quintile of diets were to shift to an "average emission" diet, he indicated that this would be equivalent to the emission reductions of cutting 66.1 million passenger vehicle miles. In fact, it is 661 million passenger vehicle miles (10 times greater than in the presentation). This amounts to 15 vehicle miles per person in that upper quintile.)